The invention relates generally to the field of geophysical data acquisition. More particularly, the invention relates to geophysical data acquisition systems that may use a single type of acquisition and signal processing device with a plurality of different types of geophysical sensors.
U.S. Pat. No. 8,026,723 issued to Loehken et al. describes a marine electromagnetic and seismic sensing cable system. The described system includes one or more acquisition units disposed along the sensing cable. The unit(s) include a number of separate signal inputs that are connected to various types of geophysical sensors, for example, magnetometers, magnetic field amplitude sensors, seismic particle motion sensors, seismic pressure or pressure gradient sensors and electric field sensors. Each signal input may have circuitry that is specific to the type of sensor coupled thereto. Output of the circuitry may be multiplexed to an analog to digital converter. Digitized signal measurements may be conducted to a recording unit and/or to a data storage device. The disclosed system requires that a specific type of geophysical sensor to be coupled to a signal input have the required circuitry for such sensor. Thus, the types of sensors that may be used and their electrical and mechanical configuration may be limited.
There is a need for a more flexible acquisition system that may be used with a plurality of different sensors while simplifying and standardizing the circuitry used to process signals from the various geophysical sensors.